Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis
- 4.4k Downloads
A number of resistance training (RT) program variables can be manipulated to maximize muscular hypertrophy. One variable of primary interest in this regard is RT frequency. Frequency can refer to the number of resistance training sessions performed in a given period of time, as well as to the number of times a specific muscle group is trained over a given period of time.
We conducted a systematic review and meta-analysis to determine the effects of resistance training frequency on hypertrophic outcomes.
Studies were deemed eligible for inclusion if they met the following criteria: (1) were an experimental trial published in an English-language refereed journal; (2) directly compared different weekly resistance training frequencies in traditional dynamic exercise using coupled concentric and eccentric actions; (3) measured morphologic changes via biopsy, imaging, circumference, and/or densitometry; (4) had a minimum duration of 4 weeks; and (5) used human participants without chronic disease or injury. A total of ten studies were identified that investigated RT frequency in accordance with the criteria outlined.
Analysis using binary frequency as a predictor variable revealed a significant impact of training frequency on hypertrophy effect size (P = 0.002), with higher frequency being associated with a greater effect size than lower frequency (0.49 ± 0.08 vs. 0.30 ± 0.07, respectively). Statistical analyses of studies investigating training session frequency when groups are matched for frequency of training per muscle group could not be carried out and reliable estimates could not be generated due to inadequate sample size.
When comparing studies that investigated training muscle groups between 1 to 3 days per week on a volume-equated basis, the current body of evidence indicates that frequencies of training twice a week promote superior hypertrophic outcomes to once a week. It can therefore be inferred that the major muscle groups should be trained at least twice a week to maximize muscle growth; whether training a muscle group three times per week is superior to a twice-per-week protocol remains to be determined.
KeywordsResistance Training Muscle Group Muscle Growth Weekly Training Lean Tissue Mass
Compliance with Ethical Standards
No external sources of funding were used to assist in the preparation of this article.
Conflicts of interest
Brad J. Schoenfeld, Dan Ogborn, and James W. Krieger declare that they have no conflicts of interest relevant to the content of this review.
- 8.Arazi H, Asadi A. Effects of 8 weeks equal-volume resistance training with different workout frequency on maximal strength, endurance and body composition. Int J Sports Sci Eng. 2011;5(2):112–8.Google Scholar
- 12.Carneiro NH, Ribeiro AS, Nascimento MA, et al. Effects of different resistance training frequencies on flexibility in older women. Clin Interv Aging. 2015;5(10):531–8.Google Scholar
- 15.McLester JR, Bishop P, Guilliams ME. Comparison of 1 day and 3 days per week of equal-volume resistance training in experienced subjects. J Strength Cond Res. 2000;14:273–81.Google Scholar
- 20.Brazzel-Roberts JV, Thomas LE. Effects of weight training frequency on the self-concept of college remales. J Appl Sports Sci Res. 1989;3(2):40–3.Google Scholar
- 21.Cooper H, Hedges L, Valentine J. The handbook of research synthesis and meta-analysis. 2nd ed. New York: Russell Sage Foundation; 2009.Google Scholar
- 23.Borenstein M, Hedges LV, Higgins JPT. Effect sizes based on means. In: Introduction to meta-analysis. UK: John Wiley and Sons, LTD; 2009. p. 21–32.Google Scholar
- 29.Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale: Lawrence Erlbaum; 1988.Google Scholar
- 31.Raastad T, Kirketeig A, Wolf D, et al. Powerlifters improved strength and muscular adaptations to a greater extent when equal total training volume was divided into 6 compared to 3 training sessions per week. 17th Annual Conference of the European College of Sport Science, Brugge, 2012.Google Scholar